Rud Istvan has a very instructive article at Judith Curry's Climate Etc. blog about the challenges of bring wind and solar power into use through electricity grids. Bottom line: Their intermittency greatly increases the costs of electricity while reducing its reliability, bringing threats to people's health and safety wherever they begin to make up a significant percentage of total power supplied to the grid. The higher the renewable penetration, the greater this intermittency burden becomes. … [Read more...]